(Reuters) - Pierluigi Collina, the chairman of the FIFA Referees Committee, has warned of a global shortage of match officials if efforts are not made to tackle abuse and violence towards referees at the grassroots level.

Collina, who was in charge of the 2002 World Cup final between Brazil and Germany, said it is a "real threat" when match officials face verbal and physical abuse in amateur football.

"It's a worldwide problem that we need to consider and we need to take (action) as soon as possible," Collina told Sky Sports.

"We have a huge number of referees working every weekend in grassroots and amateur football. At this level there is something as a threat; it's a physical threat of violence.

"Unfortunately, at this level, instead of paying huge respect for these unknown heroes... they are abused verbally, physically sometimes, this is a real threat."